BMW Rennsport 500 RS 54

who can help me sort out the technical differences between the production racer RS 54 and the works racers of the same period?

Where can I find some description about that?

There must have been 24 production racers in 1954. How many were solos and how many sidecar outfits then? How many works racers added to this number? Who were the first owners/riders? How many engines were sold or given by BMW works after those first 24 in the following years? What were the specifications of those types 253 and 256? How did they call the single steps of evolution/development, for example from long stroke to short stroke? Did they carry printed numbers on the body of the engine? How many engines of that kind are out there all over the world today?

Hi Lothar, I'm afraid these records you are looking for are only accessible in BMW's own historic files if these figures were ever written down and preserved. Since you are a member of BMW's vintage club, I assume that BMW themselves can't provide these details though ?
Only 2 names spring to my mind who could be helpful in this context: Either Gustl Lachermeier, if he is still with us, or Rudi Mannetstetter, the latter still very active in the BMW vintage scene and probably the living BMW encyclopedia. Cheers

Edit:

'How many engines were sold or given by BMW works after those first 24 in the following years?'

As far as I know, none after the original batch. Spare parts could not be obtained freely, only when damaged parts were given back. That's why Helmut Fath had to built his own engine since BMW was not willing to sell him anything after he had given his machinery away to Kölle after his Nürburgring crash in '61